1. Properties and Classification of Matter How can we describe and identify matter?

2. What is matter? Anything that has mass and takes up space is called matter In chemistry, we study what matter looks like, the composition of matter, and how matter changes.

3. What does matter “look like?”

4. What is a property? A property is something that describes what the substance looks like, or how it behaves Chemists observe the substance and identify all the unique characteristics. Chemists can then use those properties to identify a sample of unknown matter.

5. Properties can be physical or chemical Physical PropertiesChemical Properties How a substance “looks” Can observe without changing the identity of the substance Example- Silver is lustrous, or shiny. ▫In order to determine that silver is shiny, did you have to make the chemical change into something else? How a substance behaves Have to change the identity of the substance Example- Alcohol is very flammable ▫How can you determine if something catches fire easily? ▫What happens to that substance when it does catch fire?

6. More examples of Physical properties Color, odor, texture, density, magnetic, conductivity Lustrous – how shiny a metal is Ductile – how easily a metal is hammered Malleability – how easily a metal is bent ▫Aluminum has a high malleability Hardness – the ability to scratch another substance and/or be scratched by another substance ▫A diamond is the hardest substance – can scratch any other substance, cannot be scratched by anything except another diamond

7. Physical properties that require a physical change Melting point Freezing point Boiling point Ability to dissolve ▫All of these changes will NOT CHANGE the identity of the substance ▫If ice melts into liquid water, is it still H2O?

8. Examples of Chemical properties Flammability – how easily a substance catches on fire Reactivity – how easily a substance reacts to form a new substance ▫A substance that does not easily react is also said to be STABLE Volatility – how easily a liquid becomes a vapor

9. Examples of Chemical Properties Stability/reactivity Toxicity pH Fermentation Oxidation Flammability

10. DANGER!!!!!! Hazardous: material that can burn, explode, damage skin, or poison someone. Highly Reactive: always use safety goggles High Corrosive: able to burn organic material ▫Examples of corrosive materials: acids and bases

11. Properties can also be intensive or extensive Intensive PropertiesExtensive Properties Think interior, its what’s on the inside that counts Does not depend on the amount that you have Example: Density ▫The density of gold will always be 19.3 g /mL. It does not matter if you have a tiny gold coin, or a huge block of gold Think exterior, its all about appearances… DOES depend of the amount you have Example: Mass ▫If I have 2 blocks of gold, and you have 10 blocks of gold, is that different?

12. You hear that gold has been found in California! You rush there to try and get rich. You are searching, and you think you have found a sample of pure gold! Describe what you can do to prove that the gold you have found is not fake. You must use the 9 of the following 14 words: propertychemical physicalintensive extensivedensitymalleability lustrousdissolvemeltingboiling matterconductivitymagnetic

13. Physical Changes  A change that alters the physical properties of a substance but does not change its identity  Physical changes do not form new substances!  EX:  sugar dissolving  Cutting of paper (change in shape or size)  Phase changes (solid-liquid-gas)  Physical changes are easy to undo (with some exceptions!)

14. Chemical Changes A process involving one or more substances changing into new substances You can observe chemical properties only when a chemical change occurs! New substances with different properties are formed Examples: – baking a cake – iron reacting with oxygen to form rust

15. Evidence of Chemical Change Gas/Vapor produced Color change Temperature change Burning Tarnish/rust Precipitate (a solid) is produced New odor Light is produced Bubbles

16. What do we call it?

17. How can we put matter into groups? Chemists use the following to group matter into categories ▫How simple it is ▫If and/or how it can be separated ▫How it is combined with other substances

18. Pure Substances: Elements Simplest form of matter Cannot be separated by any means Not combined with any other elements Can find on the periodic table Examples: Gold (Au), Iron (Fe), Oxygen (O2) ▫Look for 1 capital letter!

19. Pure Substances: Compounds Two or more elements chemically combined Can be separated by chemical means (like a chemical reaction) Cannot be separated by physical means Examples: Water (H2O), Carbon dioxide (CO2), Chalk or Calcium carbonate (CaCO3) ▫Look for more than 1 capital letter!

20. Mixtures Two or more pure substances mixed together Can be separated by physical means, such as filtration, or heating Examples: Soup ▫How can you physically separate the parts of soup? Can be Homogeneous or Heterogeneous

21. HETEROGENEOUS MIXTURE ELEMENT yes no Examples: granite rock, beach sand, cereal, Matter Can it be separated by physical means? Is it composed of the same stuff? yesno MIXTURE PURE SUBSTANCE Is the composition variable? Can you see chunks of different things? Can it be separated by chemical means? Does it contain more than one chemical element? Does the chemical formula have more than one capital letter? HOMOGENEOUS MIXTURE COMPOUND yes no Examples: air, sugar water, stainless steel, salt water Examples: water, salt, quartz, glucose Examples: oxygen, gold, aluminum, iron

22. Is it an : ELEMENT COMPOUND MIXTURE

23. Element!

24. Compound!

25. Homogeneous Mixture

26. Soil Heterogeneous Mixture

27. Element

28. Heterogeneous Mixture

29. States of Matter Notes

30. The Three States of Matter Solid Liquid Gas

31. Basis of Classification of the Four Types The Classification and Properties of Matter Depend Upon Microscopic Structure  Particle arrangement  Particle kinetic energy  Particle to particle distance

32. The state of matter can be altered by: adding or removing energy (AKA heat) and/or pressure This can affect the arrangement and energy of the particles.

33. Solids  Shape:  Have a definite shape  Volume:  Have a definite volume.  KE:  Particles of solids are tightly packed, vibrating about a fixed position therefore they have the lowest kinetic energy of the three states  Compressibility:  Solids are not easily compressible and are not fluid because there is little free space between particles.

34. Solids Particle Movement Examples

35. Liquids  Shape:  indefinite shape because the particles can slide past one another  Volume:  definite volume  KE:  More kinetic energy than a solid because particles of liquids are tightly packed, but are far enough apart to slide over one another.  Compressibility:  not easily compressible because there is little free space between particles. (more compressible than a solid)  Liquids are fluid because the particles can move/slide past one another.

36. Liquids Particle Movement Examples

37. Gases  Shape:  indefinite shape because particles can move past one another.  Volume:  indefinite volume because the particles can move past one another.  KE:  Gases have high kinetic energy (molecules move the fastest of the three) because particles of gases are very far apart and therefore move randomly.  Compressibility:  Gases are easily compressible because there is a great deal of free space between particles.  Gases are fluid because the particles randomly move past one another.

38. Gases Particle Movement Examples

39. Comparison The Classification and Properties of Matter Depend Upon Microscopic Structure  Particle arrangement  Particle kinetic energy  Particle to particle distance

40. Heating Curve of Water

41. ?????????? When a substance changes from a solid to a liquid, what normally happens to its density? Why? (Think of the density formula.) Why does water not follow that general rule?